:root {
    --primary-color: #4a90e2;
    --secondary-color: #34495e;
    --accent-color: #2ecc71;
    --text-color: #333;
    --light-gray: #f5f6fa;
    --white: #ffffff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    font-size: 16px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background: var(--white);
    padding: 1rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--secondary-color);
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--white);
    padding: 8rem 0 4rem;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
}

/* CTA Buttons */
.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.cta-button {
    padding: 1rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: transform 0.3s;
}

.cta-button:hover {
    transform: translateY(-2px);
}

.cta-button.primary {
    background: var(--accent-color);
    color: var(--white);
}

.cta-button.secondary {
    background: transparent;
    border: 2px solid var(--white);
    color: var(--white);
}

/* Sections */
.section {
    padding: 4rem 0;
}

.section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--secondary-color);
    font-size: 2.5rem;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s;
    font-size: 1.1rem;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: var(--secondary-color);
    font-size: 1.8rem;
}

.feature-card ul {
    list-style: none;
    text-align: left;
}

.feature-card ul li {
    margin-bottom: 0.5rem;
    padding-left: 1.5rem;
    position: relative;
}

.feature-card ul li:before {
    content: "•";
    color: var(--primary-color);
    position: absolute;
    left: 0;
}

/* Download Section */
.download-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.download-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    text-align: center;
}

.download-card i {
    font-size: 3rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.download-button {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background: var(--primary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 5px;
    margin-top: 1rem;
    transition: background-color 0.3s;
}

.download-button:hover {
    background: var(--secondary-color);
}

.testflight-guide {
    margin-top: 1rem;
    font-size: 0.9rem;
    text-align: left;
}

/* Contact Section */
.contact-info {
    text-align: center;
    padding: 1rem;
}

.contact-info p {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 1.2rem;
}

.contact-info i {
    color: var(--primary-color);
}

.email-image {
    height: 20px;
    vertical-align: middle;
    margin-left: 8px;
}

.contact-form {
    max-width: 600px;
    margin: 0 auto;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 0.8rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.contact-form button {
    background: var(--primary-color);
    color: var(--white);
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.contact-form button:hover {
    background: var(--secondary-color);
}

/* Footer */
footer {
    background: var(--secondary-color);
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

.footer-links {
    margin-top: 1rem;
}

.footer-links a {
    color: var(--white);
    text-decoration: none;
    margin: 0 1rem;
}

/* 开源信息样式 */
.open-source-info {
    text-align: center;
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--light-gray);
    border-radius: 10px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.highlight-text {
    font-size: 1.3rem;
    color: var(--primary-color);
    font-weight: bold;
    margin-bottom: 1rem;
}

.repo-link {
    font-size: 1.2rem;
}

.repo-link a {
    color: var(--secondary-color);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: color 0.3s;
}

.repo-link a:hover {
    color: var(--primary-color);
}

.repo-link i {
    font-size: 1.4rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
    }
    
    .feature-card {
        margin-bottom: 2rem;
    }
}

#intro p {
    font-size: 1.25rem;
    line-height: 1.8;
    max-width: 900px;
    margin: 0 auto;
}